After you have downloaded and installed the SharePoint Meeting Organizer you have to activate the features Calendar E-Mail Extension and Calendar E-Mail Extension – Meeting Organizer in your Site Collection Features.
The Meeting Organizer functionality can be configured using the Calendar E-Mail Extension settings in the list settings of your calendar lists.
In the settings page you can configure 2 e-mail addresses:
The first e-mail address is needed to enable the Calendar E-Mail Extension to have basic functionality like send meeting request and handle attendee’s responses. To use this feature you have to create an event from the “Event (with e-mail extension)” content type. Read more about configuring an “Event (with e-mail extensions)” content type here: Configuring the SharePoint Calendar E-Mail Extension 3.0.
The second e-mail address is needed to extend the SharePoint Calendar with additional Meeting Organizer functionality like handle incoming meeting requests, create meeting workspaces automatically and take over the meeting organizer role.
If you want the SharePoint Calendar to create meeting workspaces automatically you have to check the “create meeting workspaces” check box and select a workspace template to be applied if the calendar receives meeting requests. You can also specify if missing “create subwebs” permissions should be overridden, or if no workspaces should be created if the sender doesn’t have this permission.
You can also change the e-mail body, which the sender will receive after a meeting workspace is created.
The external server name field is important if intranet users access your calendar site with a different server name. If you configure the external server name, the workspace link will contain the external server name. Make sure all users can access it.
If you enable the “Take over the organizer role” check box, the calendar will send meeting requests to all attendees. More information can be found in this post: How to: Enforce your meeting organization policy.
Finally you can specify whether to save e-mail attachments and the e-mail security policy.
Save the settings and make sure the “Event (with E-Mail Extension)” is your default content type.
Important: Use the 2nd e-mail address to send a meeting request to your SharePoint Calendar. The first e-mail address is used to send Meeting Request from the SharePoint Calendar to the attendees configured in an event (with e-mail extension).